PCLinuxOS is not Debian / Ubuntu based. Unlike Debian / Ubuntu which uses .deb it uses .rpm package management system with apt-get. It's default desktop is KDE. PCLinuxOS has an excellent Wiki which will be very useful to anyone wanting to learn Linux and KDE. Though you will find articles which are exclusively applicable to PCLinuxOS, which you should ignore for applying it to Ubuntu based distros, it's wiki is well documented and very informative.